Rapidly Progressive Glomerulonephritis (RPGN).

Type I RPGN (Anti-GBM Antibody)

Idiopathic

Goodpasture syndrome

Type II RPGN (Immune Complex)

Idiopathic

Postinfectious

Systemic lupus erythematosus

Henoch-Schönlein purpura (IgA)

Type III RPGN (Pauci-Immune)

ANCA associated

Idiopathic

Wegener granulomatosis

Microscopic polyarteritis nodosa/microscopic polyangiitis

proliferation of the parietal epithelial cells of Bowman's capsule in response to injury and in part by infiltration of monocytes and macrophages forms crescents

crescents eventually obliterate Bowman's space and compress the glomeruli

Crescentic glomerulonephritis (PAS stain). Note the collapsed glomerular tufts and the crescent-shaped mass of proliferating cells and leukocytes internal to Bowman capsule.